We will continue our efforts to synthesize model retinals each of which when incubated with opsins are designed to give specific model visual pigments that will clarify various aspects of the visual transduction process. We will carry out experiments to further check the validity of our external point-charge model recently proposed to account for the wide variance in absorption maxima (460-630nm) of visual pigments of different sources. Simple molecules are being constructed to check the double point-charge model for bacteriorhodopsin. Some of the synthetic retainals will lead to pigments having their maxima in the near IR. The syntheses of photoaffinity labeled retinals are also in progress.